Blowing device for pneumatic tools



March 21,1933. E. B. LEAR 1,902,562

BLOWING DEVICE FOR PNEUMATIC TOOLS Filed Aug. 6, 1931 mmvrog. rLBJJcau HIS/ATTORNEY Patented Mar. 21, 1933 UNITED STATES EARL B. LEAR, or rHILLIrsBUnG, NEWJERSEY, ASSIGNOR ro INGERSOLL-RAND' con:- i

PATENT orrien PANY, OF @TERfiEY CITY, ERSEY, A CORPORATION (3F I-IEVJ JERSEY BLOWING nnvr'on non PNEUMATIC TOOLS Application filed au ust 6, 1931. Serial No. 555,415.

This invention relates to. pneumatic tools, but more particularly to a blowing device for pneumatic percussive tools employed for actuating hollow working implements through which a cleansing mediummay be introduced into the drill hole. I f

One object of the invention istoJefi'ect a thorough cleansing of the .hole being drilled,

both during the operating and idle periods of obvious and matic tool equipped with a blowing device constructed inaccordance with the practice of the invention, and .Figure 2 is a transverse view taken throng Figure 1 on the line 22 looking in the direction indicated by the arrows.

Referring more particularly to the drawing, A designates generally apneumatic tool comprising a cylinder B having a piston chamberG therein to accommodate a reciprocatory hammer piston D. The piston chamber C is provided with a free exhaust port E controlled by a head F of the hammer piston D.

The piston D is provided with a forwardly projecting stem G shown, for convenience of illustration, as being guided in a bore H in the cylinder B and terminating at its front end in an enlarged cavity J Opening from the front end of the cylinder B and communicating at its rear end with the cavity J is a bore K to accommodate the shank of a working implement L which projects with its rear end into the cavity J to receive the blows of the hammer piston D.

The rear end of the cylinder B is provided in this instance with exterior threads .0 for cooperation with threads of a'hood Q. Disposed within a bore, R in the hood Q, and

seated upon the rear end of the cylinder is a plate S which acts as a closure for the r rear end of the piston chamber and the rear end of said plate serves as a seat T for a valve U of the oscillatory plate type. 1 1 1 a The opposite ends of wings of the valve U control the admission of pressure. fluid to the piston chamber. Such pressure fluid is conveyed from a valve chamber Vin the hood Q,

and wherein the valve U is arranged, into the rear end of the piston chamber by a rear; inlet passage W in the plate S. The plate S is further provided with a front inlet-pass sage X which extends through the wall of the cylinder B and opens into; the front end of the piston chamber O. t V The tool A illustrated as being of the hand held type is accordingly provided with a,

handle Y whereby it may besupported, conveyed and held to the work. The handle Y;

is held in suitably spaced relation with re spect to the rear end of the hood Q bystandards Z, only one of which is shown and which,

as is customary, may form anintegra l part 7 of the hoodQ. I g I The admission of pressure fluid employed for operating the tool A is controlled by ,a

throttle valve 6 inthe hood Q. The throttle valve 6 is preferably of therotary type having a handle or leverc for its manipulation. The throttle valve has a central chamber d which may be in constant communication with a source of pressure fluid. In thewall of the throttle valve 6 is a port etwhich is adapted to register with a supply passage f in the hood Q. and opening into the valve chamber V. i a ,1 I

In accordance with the practice-of the invention', means are provided for selectively introducing anuninterrupted supply of pressure fluid through the drill steel intothe drill hole'to effect the removal of cuttings'there-- from and thus assure a clean working sur face for the cuttingbit of the drill steel L and to effect such blowing either during the operative or: inoperative periods of the tool.

sage h which communicates at one end with a passage 9 and at its other end with a pas sage in a bushing k which is seated with one end in the plate S and with its other end in the hood Q. The bushing 70 is arranged axially of the valve chamber V and extends through the valve U to act as a guide for said valve.

' In the rear end of the hood Q, and arranged coaXially' with the bushing 70 is a bore which serves as a blower valve chamber 0 and wherewith the rear end of the passage j of the bushing k communicates.

Arranged rotatably within thevalve chamber o is a blower valve p having a lever 9 whereby sald valve may be rotated from one position to another. The valve 10 is prefer- ,the chamber 0, a spring 1) is disposed within a recess w in the valve 39 to act withione end thereagainst and with its other end against the bushing for holding the valve 19 immovable in its limiting positions and for holding the bushing la firmly seated in the plate S. V

In the wall of the valve p and in communication with the recess w is a port m which is adapted to register with a passage 3 in'the hood Q, and leading from the valve chamber 0 to a chamber or bore 2 wherein the throttle valve 6 is arranged. The throttle valve is preferably provided with an annular groove 2 in its periphery to assure constant communication between the passage :0 and a port 3 in the wall of the throttle valve 1).

The operation of the device is as follows: Whenever during the operation of the tool cuttings accumulate in the drill hole to such an extent as to interfere with the elficient cutting of the bit of the working implement the blower valve p may be rotated to the position illustrated in Figure 1 wherein the port at will be brought into registry with the passage y. The blower valve may be thus positioned, as desired, either when the hammer pistonD is in operation or idle.

With the blower valve 7) in the position described pressure fluid will flow from the throttle valve 5 through the passage 1 and the port 00 into and through the valve 2,

thence through the passages j and 9 into the cavity J. From there the pressure fluid will flow through the drill steel L into the drill hole and blow the cuttings therefrom.

After the'drill hole has been cleansed the blower valve ;0 may again be rotated to its closed position wherein it will be securely held against the effects of vibration, incident to drilling, by the'action of the spring '4) which will then retain the blower valve ;0 in position to assure engagement between. the notch u and the reduced end s of the screw 1*.

In practice the present invention-has been found to be highly efficient. Owingto the. construction described the blower valve p may be conveniently located beneath the handle Y so that itmay be readily manipulated without requiring the operator to release his grip onthe handle.

I claim:

A pneumatic tool comprising a casing having a piston chamber, a hammer piston therein, a hollow drill steelg'uided by the casing, an automatic valve to distribute pressure fluid to the piston chamber, a blower passage in the casingand being in constant communication' with the interior of the drill steel, a bushing in the casing communicating with the passage and extending through the auto-- matic valve to act as a guide therefor, a blower valve to connect the bushing with a source to selectively supply pressure fluid through the passage to the'drill steel during the operating and idleperiods of the piston and being arranged coaxially with the bushing, and a spring interposed between the bushing and the blower valve to hold the blower valve immovable in its limiting positions and to hold the bushing firmly seated in the casing. I

' In testimony-whereof I have signed this specification.

EARL I B. LEAR. 

